196 THE SNAKES OF SOUTH AFRICA. 
frequently kept Green Mambas in captivity for the purpose of 
studying their habits. They are at first exceedingly active, and 
evince a disposition to bite if approached. However, they soon 
lose all spirit, and will allow themselves to be freely handled 
without showing any alarm. Those I kept in captivity were 
bright grass-green at first, but gradually darkened in colour. I 
was unable to keep them alive long enough to ascertain if they 
would eventually have changed to olive-brown or blackish. The 
existence of a green variety of Mamba is either doubted or posi- 
tively denied by most Colonists. There is no doubt at all of its 
existence. I have examined many. Their poison fangs, other 
teeth and scale formation were similar to these distinguishing 
characters in the Black Mamba. 
I have never met with the green variety of Mamba anywhere 
but the coastal districts of Natal in the dense forests. In the 
uplands of Natal and Zululand I have only seen the Black variety. 
A controversy has been, and is, waged as to whether the 
Green Mamba remains green all its life, or gradually darkens in 
colour with age. The so-called Black Mamba is usually olive- 
black in colour, varying in its degrees of intensity. Some speci- 
mens are uniformly dark olive or olive-black, others have the tips 
of the scales edged with black. Green Mambas of all lengths up 
to eight and nine feet have been frequently observed. 
On the contrary, Black Mambas have been killed which 
measured thirteen feet from nose to tip of tail. It is almost a 
daily occurrence for Black Mambas, averaging eight to nine feet 
in length, to be killed in Natal, Zululand, and Transvaal. 
Green Mambas are always found in the forests, clumps of 
tangled creeper-covered bush, and wooded valleys. The Black 
Mamba is often found in more open situations, and wanders far 
afield, and even penetrates the dwellings of man. It is quite a 
common occurrence for Black Mambas to be found in the thatch 
of old farm buildings, or amongst the refuse near by, drawn there 
by the presence of rats and mice. I have several times seen and 
killed Black Mambas in trees on the outskirts of the forests, or 
on branches overhanging beaten tracks, where they lie watching 
for rodents and other prey, but I found them more abundantly 
on the ground basking in the sun on the bare sloping sides of 
streams and dongas. On being alarmed, they rapidly glided off 
to a hole, into which they vanished. 
